SOURCE: St. Lawrence Seaway Traffic Reports, 2002-2006, produced by the U.S. St. Lawrence Seaway Development Corp. and Canadian t. Lawrence Seaway Management Corp..

Laker vessels that transit the Seaway lock system are primarily Canadian-fl agged domestic
self-unloader bulk vessels. There are approximately 80 vessels in the Canadian domestic
fl eet. Because the Canadian lakers are much smaller than U.S.-fl agged lakers, they are able
to visit ports throughout each of the fi ve Great Lakes, and in some cases, Canadian ports
outside the Great Lakes Seaway System. In general, Canadian lakers carry coal, iron ore,
and limestone, accounting for nearly two-thirds of the cargo carried. Other cargoes carried
include tanker products, grain, salt, miscellaneous bulk, and cement. The primary pattern for
Canadian lakers is to transport grain from Thunder Bay and Duluth-Superior to ports along
the St. Lawrence River.

The transoceanic vessel fl eet that uses the Seaway System comprises approximately 220
vessels fl agged in more than 30 countries. The vast majority of vessels are bulk carriers,
though there are also a small number of general cargo carriers, heavy lift ships, and tankers
in service. With the exception of barges, ocean vessels are by far the smallest vessels
operating on the Lakes, with most vessels approximately 180 meters in length. This smaller
size enables them to enter the lakes from overseas, transit the St. Lawrence Seaway, Welland
Canal, and all fi ve Great Lakes. Ocean vessels generally follow a "steel in-grain out" trade
pattern, whereby iron and steel, and other high value cargoes generally arrive from Europe,
and are discharged in a series of lower Great Lakes ports.

Noncargo vessels include passenger, military, and other noncommercial ships.